Both sides can admit that the opponents have some strengths and good qualities, and are not total jerks despite how you feel about them sometimes.

I hope you're staying with me this far, because the meat is coming up. What makes one side's values so different: A different emphasis. That is, the sense that certain values are much more important than other values. So the key is not that the opponent's values are bad, corrupt, or stupid, but that they're not the right values to emphasize.

The best way absorb this point is through a handy example--the difference between progressive values and conservative, as illustrated by these morsels from the web.

Progressives emphasize values that support the human family, that is, values such as inclusion, compassion, community, and nurturing. Lesser, but still important values are fair markets, active citizenry, and rule of law.

Conservatives emphasize values that support self-reliance, truth, hard work, and the ability to resist lots of human weaknesses such as addiction, depression, and fear. Lesser, but still important values are humility, open-mindedness, and a tempered respect for authority.

Conservatives can look at the progressive's list and agree that the values are OK (maybe with a few exceptions), but not the most important. Ditto for the progressive looking at the conservative's list.

So, what separates the conservative and the progressive is what values they think are most important. However, this has a huge effect. For example, the ideal conservative world probably looks quite different from the ideal progressive world. (I won't actually engage in considering these ideal worlds because I don't waste my time on politically-tinged fantasy worlds.... gag!)

Another big difference is how to promote or achieve these values, what methods are effective, and what are appropriate spheres for taking action or addressing needs. Even then, you won't find total disagreement. Conservatives think that the federal government is the right vehicle for certain tasks, and so do progressives. It's just the tasks are different, say national defense versus providing healthcare.

So, to recap again:

There are good values on many sides.

There is no absolute way to show one set of values is better than another.

The differences in viewpoint often come down to a different emphasis on what is most important, how to achieve goals, how to provide for needs, and what spheres or methods are most effective.

None of these can be judged absolutely, so judgment is always subjective.

Nonetheless, people can and do make judgments and choose the most important values to uphold and promote. With consideration, you can weed out the bad ideas. With even more consideration, you can weed out good-but-not-good-enough ideas. This is what I try to do.